BARCELONA, Spain — Many readers probably have a cursory notion of the recent turmoil plaguing the autonomous Spanish region of Catalonia. They will have seen large demonstrations by both separatists and unionists. They may know, too, that following the illegal referendum on independence, Catalan separatist politicians, with 47 percent of the votes and a majority in the Catalan Parliament, decided to suspend the laws concerning the region’s relationship with the central government. They then fraudulently approved a transitory constitution and an act calling for an illegal plebiscite on a plan for secession.

Weeks later, the regional president, Carles Puigdemont, declared unilateral independence, forcing the Spanish government to intervene to restore constitutional order and to schedule regional elections. Mr. Puigdemont, now deposed, fled the country and is in Belgium trying to rally support from other European countries, while Spain has issued an international warrant for his arrest. Aware that no European country will support his demands, last week he said that Catalans should decide if their region should leave the European Union.

Readers probably do not, however, have a clear understanding of how this has come to pass in a prosperous European democracy known for its freedom, tolerance and largely self-governed autonomous regions. We Catalans owe the world an explanation.

I was born in Barcelona in 1979. My father is Catalan, the son of a family of merchants, and my mother was born in Andalusia to a humble and hard-working family. In the early 1970s, like millions of Andalusians, they moved to Catalonia in search of opportunities and to pursue their dreams. My parents met in Barcelona, where they married. In 1989, they started their own business, which allowed them to live comfortably. Three years ago, the economic crisis drowned the family company, and today my mother and aunt raise every day the shutter on a smaller homemade food venture. In recent weeks, my parents’ business has suffered attacks by separatist radicals.

Origin and socioeconomic status are the variables that best explain secessionism in my region: The higher the income and deeper the Catalan roots, the greater the separatist support; the lower the income, particularly among those with strong links to the rest of Spain, the greater the preference for a united Spain. This turns Catalan nationalism, traditionally conservative and oligarchic, into a movement through which those who have more want to emancipate themselves from the rest.

It’s not trivial that a Catalan like me should have the honor of being a candidate for prime minister of Spain, a fact that contrasts with the Francoist and repressive caricature that the separatists try to sell of Spain. In fact, the Spanish Constitution, approved in 1978, was endorsed with 91 percent support in Catalonia, and two of the seven founders of the Constitution were Catalans.

In 1979 Spain was a young constitutional monarchy seeking integration with Western Europe. Today it is one of the most important economies of the European Union, as well as one of the most decentralized countries with the highest standards of democracy, freedom and social welfare rates in the world.

But in Catalonia we are facing a serious social fracture. Catalan nationalism has grown notably in recent years, spurred by a decade-long economic crisis and corruption scandals that have generated mistrust in political institutions. The separatist movement parallels populist movements in other Western countries in response to globalization and its economic and political challenges: “Subsidized Spain lives at the expense of productive Catalonia” read an electoral poster from Mr. Puigdemont’s political party; separatists also employ an even blunter slogan, “Spain robs us.”

Still, Catalan separatists have been very smart. The movement has taken the old exclusionary nationalism, founded on the thesis of a cultural, economic and linguistic difference, and rebranded itself as peace-loving and democratic.

Behind this makeover a sense of supremacy defines this movement. It is seen in the use over the past three decades of propaganda in the public media and in the education system, which has been used as a brainwashing machine for the separatist movement started five years ago.

All this has been exacerbated by both Socialist and conservative governments in Madrid. To obtain the support of the nationalist parties in the Spanish Congress of Deputies, they gradually ceded privileges and authority to the nationalist governments in Catalonia without supervision or coordination.

Catalan nationalists have also persistently promoted the idea of a referendum. Those of us opposed to the plebiscite believe that not all democratic principles can be put to popular vote. Civil rights are not negotiable. Millions of Catalans cannot be deprived of their Spanish and European citizenship while national sovereignty is dissolved, and with it the right of all Spaniards to decide together on the future of Spain.

On occasion, the federal government of the United States has also had to intervene to safeguard the rights of minority groups who have been trampled underfoot. President John F. Kennedy said in 1962, also in a context of disobedience and rights violations by local government, that citizens are “free to disagree with the law, but not to disobey it,” and that, in a country where the courts and the Constitution are challenged, “no law would stand free from doubt, no judge would be sure of his writ, and no citizen would be safe from his neighbors.”

This is what is happening in Catalonia.

Separatist leaders would replace the Constitution with arbitrariness; judges are being pressured for doing their jobs; the social climate has deteriorated to the point of dividing families and friends. Political instability has also led to the exodus of thousands of businesses and a loss of tourism in Barcelona, one of the world’s most attractive cities.

Fortunately, the Constitution allows the national government to hold democratic elections on Dec. 21. We Catalans will be able to vote in legal regional elections to put an end to this madness. Never before has a regional government done so much economic, social and moral damage to Catalonia as it has with Mr. Puigdemont and the deposed vice president Oriol Junqueras at the helm.

Ciudadanos, the party I preside over, began from a Catalan civil movement representing a majority of Catalans silenced by Catalan nationalism. Today we are the leading opposition party in Catalonia, and a national and European party aspiring to govern Spain.

As most Spaniards do, a majority of Catalans want to participate in a common project for the future of Spain. I cannot resign myself to seeing an isolated Catalonia in a globalized world, nor can I resign myself to seeing more borders in the era of open societies.

Faced with those who promote rupture, I demand dialogue. Faced with exclusion, I ask for coexistence; federalism and union, not provincialism and division; the rule of law, not arbitrariness; and pluralism and freedom against dogma and imposition.

I was born in Barcelona. Catalonia is my homeland, Spain is my country, and Europe is our future.

Albert Rivera is the president of the Ciudadanos party and a candidate for prime minister of Spain.